patch 9.1.0184: Cursor pos wrong when clicking with conceal and wrap

Problem:  Cursor position wrong when clicking with conceal and wrap.
Solution: Use the virtual column of the last char for ScreenCols[] in
          boguscols.  Remove use of MAXCOL in ScreenCols[].  Rename
          third argument of wlv_screen_line() to "clear_end" as that's
          clearer what it does (zeertzjq).

related: 14192
closes: #14200

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/drawline.c

@@ -832,9 +832,10 @@ text_prop_position(
  * Call screen_line() using values from "wlv".
  * Also takes care of putting "<<<" on the first line for 'smoothscroll'
  * when 'showbreak' is not set.
+ * When "clear_end" is TRUE clear until the end of the screen line.
  */
     static void
-wlv_screen_line(win_T *wp, winlinevars_T *wlv, int negative_width)
+wlv_screen_line(win_T *wp, winlinevars_T *wlv, int clear_end)
 {
     if (wlv->row == 0 && wp->w_skipcol > 0
 #if defined(FEAT_LINEBREAK)
@@ -872,8 +873,8 @@ wlv_screen_line(win_T *wp, winlinevars_T *wlv, int negative_width)
     }
 
     screen_line(wp, wlv->screen_row, wp->w_wincol, wlv->col,
-		    negative_width ? -wp->w_width : wp->w_width,
+		    clear_end ? wp->w_width : -wp->w_width,
-		    wlv->screen_line_flags);
+		    wlv->vcol - 1, wlv->screen_line_flags);
 }
 
 /*
@@ -939,7 +940,7 @@ draw_screen_line(win_T *wp, winlinevars_T *wlv)
 	    ScreenLines[wlv->off] = ' ';
 	    if (enc_utf8)
 		ScreenLinesUC[wlv->off] = 0;
-	    ScreenCols[wlv->off] = MAXCOL;
+	    ScreenCols[wlv->off] = wlv->vcol;
 	    ++wlv->col;
 	    if (wlv->draw_color_col)
 		wlv->draw_color_col = advance_color_col(
@@ -969,7 +970,11 @@ draw_screen_line(win_T *wp, winlinevars_T *wlv)
     }
 #endif
 
-    wlv_screen_line(wp, wlv, FALSE);
+    // Set increasing virtual columns in ScreenCols[] to set correct curswant
+    // (or "coladd" for 'virtualedit') when clicking after end of line.
+    wlv->screen_line_flags |= SLF_INC_VCOL;
+    wlv_screen_line(wp, wlv, TRUE);
+    wlv->screen_line_flags &= ~SLF_INC_VCOL;
     ++wlv->row;
     ++wlv->screen_row;
 }
@@ -1928,7 +1933,7 @@ win_line(
 	    // stop here.
 	    if (number_only > 0 && wlv.draw_state == WL_NR && wlv.n_extra == 0)
 	    {
-		wlv_screen_line(wp, &wlv, TRUE);
+		wlv_screen_line(wp, &wlv, FALSE);
 		// Need to update more screen lines if:
 		// - LineNrAbove or LineNrBelow is used, or
 		// - still drawing filler lines.
@@ -1987,7 +1992,7 @@ win_line(
 		&& lnum == wp->w_cursor.lnum
 		&& wlv.vcol >= (long)wp->w_virtcol)
 	{
-	    wlv_screen_line(wp, &wlv, TRUE);
+	    wlv_screen_line(wp, &wlv, FALSE);
 	    // Pretend we have finished updating the window.  Except when
 	    // 'cursorcolumn' is set.
 #ifdef FEAT_SYN_HL
@@ -3764,7 +3769,7 @@ win_line(
 		}
 #endif
 		ScreenAttrs[wlv.off] = wlv.char_attr;
-		ScreenCols[wlv.off] = MAXCOL;
+		ScreenCols[wlv.off] = wlv.vcol;
 #ifdef FEAT_RIGHTLEFT
 		if (wp->w_p_rl)
 		{
@@ -4167,7 +4172,7 @@ win_line(
 		    if (enc_utf8)
 			ScreenLinesUC[wlv.off] = 0;
 		    ScreenAttrs[wlv.off] = attr;
-		    ScreenCols[wlv.off] = MAXCOL;  // TODO: this is wrong
+		    ScreenCols[wlv.off] = wlv.vcol - 1;
 # ifdef FEAT_RIGHTLEFT
 		    if (wp->w_p_rl)
 		    {
@@ -4184,12 +4189,12 @@ win_line(
 		    }
 		}
 	    }
-	    wlv_screen_line(wp, &wlv, FALSE);
+	    wlv_screen_line(wp, &wlv, TRUE);
 	    wlv.col += wlv.boguscols;
 	    wlv.boguscols = 0;
 	    wlv.vcol_off_co = 0;
 #else
-	    wlv_screen_line(wp, &wlv, FALSE);
+	    wlv_screen_line(wp, &wlv, TRUE);
 #endif
 	    ++wlv.row;
 	    ++wlv.screen_row;

src/drawscreen.c

@@ -1028,7 +1028,8 @@ redraw_win_toolbar(win_T *wp)
     }
     wp->w_winbar_items[item_idx].wb_menu = NULL; // end marker
 
-    screen_line(wp, wp->w_winrow, wp->w_wincol, wp->w_width, wp->w_width, 0);
+    screen_line(wp, wp->w_winrow, wp->w_wincol, wp->w_width, wp->w_width, -1,
+									    0);
 }
 #endif
 
@@ -1363,7 +1364,7 @@ fold_line(
 #endif
 
     screen_line(wp, row + W_WINROW(wp), wp->w_wincol,
-						  wp->w_width, wp->w_width, 0);
+					      wp->w_width, wp->w_width, -1, 0);
 
     // Update w_cline_height and w_cline_folded if the cursor line was
     // updated (saves a call to plines() later).
@@ -3049,7 +3050,7 @@ redraw_asap(int type)
 		    mch_memmove(ScreenLines2 + off,
 				screenline2 + r * cols,
 				(size_t)cols * sizeof(schar_T));
-		screen_line(curwin, cmdline_row + r, 0, cols, cols, 0);
+		screen_line(curwin, cmdline_row + r, 0, cols, cols, -1, 0);
 	    }
 	    ret = 4;
 	}

src/mouse.c

@@ -2098,35 +2098,7 @@ retnomove:
 	    redraw_cmdline = TRUE;	// show visual mode later
     }
 
-    if (col_from_screen == MAXCOL)
+    if (col_from_screen >= 0)
-    {
-	// When clicking after end of line, still need to set correct curswant
-	int off_l = LineOffset[prev_row] + curwin->w_wincol;
-	if (ScreenCols[off_l] < MAXCOL)
-	{
-	    // Binary search to find last char in line
-	    int off_r = LineOffset[prev_row] + prev_col;
-	    int off_click = off_r;
-	    while (off_l < off_r)
-	    {
-		int off_m = (off_l + off_r + 1) / 2;
-		if (ScreenCols[off_m] < MAXCOL)
-		    off_l = off_m;
-		else
-		    off_r = off_m - 1;
-	    }
-	    colnr_T eol_vcol = ScreenCols[off_r];
-	    if (eol_vcol < 0)
-		// Empty line or whole line before w_leftcol,
-		// with columns before buffer text
-		eol_vcol = curwin->w_leftcol - 1;
-	    col = eol_vcol + (off_click - off_r);
-	}
-	else
-	    // Empty line or whole line before w_leftcol
-	    col = prev_col - curwin->w_wincol + curwin->w_leftcol;
-    }
-    else if (col_from_screen >= 0)
     {
 	// Use the virtual column from ScreenCols[], it is accurate also after
 	// concealed characters.

src/proto/screen.pro

@@ -7,7 +7,7 @@ int compute_foldcolumn(win_T *wp, int col);
 size_t fill_foldcolumn(char_u *p, win_T *wp, int closed, linenr_T lnum);
 int screen_get_current_line_off(void);
 void reset_screen_attr(void);
-void screen_line(win_T *wp, int row, int coloff, int endcol, int clear_width, int flags);
+void screen_line(win_T *wp, int row, int coloff, int endcol, int clear_width, colnr_T last_vcol, int flags);
 void rl_mirror(char_u *str);
 void draw_vsep_win(win_T *wp, int row);
 int stl_connected(win_T *wp);

src/screen.c

@@ -452,6 +452,10 @@ skip_for_popup(int row, int col)
  * SLF_RIGHTLEFT    rightleft window:
  *    When TRUE and "clear_width" > 0, clear columns 0 to "endcol"
  *    When FALSE and "clear_width" > 0, clear columns "endcol" to "clear_width"
+ * SLF_INC_VCOL:
+ *    When FALSE, use "last_vcol" for ScreenCols[] of the columns to clear.
+ *    When TRUE, use an increasing sequence starting from "last_vcol + 1" for
+ *    ScreenCols[] of the columns to clear.
  */
     void
 screen_line(
@@ -460,6 +464,7 @@ screen_line(
 	int	coloff,
 	int	endcol,
 	int	clear_width,
+	colnr_T	last_vcol,
 	int	flags UNUSED)
 {
     unsigned	    off_from;
@@ -775,7 +780,8 @@ screen_line(
 						  && ScreenAttrs[off_to] == 0
 				  && (!enc_utf8 || ScreenLinesUC[off_to] == 0))
 	{
-	    ScreenCols[off_to] = MAXCOL;
+	    ScreenCols[off_to] =
+			      (flags & SLF_INC_VCOL) ? ++last_vcol : last_vcol;
 	    ++off_to;
 	    ++col;
 	}
@@ -830,7 +836,8 @@ screen_line(
 								 ' ', ' ', 0);
 	    while (col < clear_width)
 	    {
-		ScreenCols[off_to++] = MAXCOL;
+		ScreenCols[off_to++]
+			    = (flags & SLF_INC_VCOL) ? ++last_vcol : last_vcol;
 		++col;
 	    }
 	}

src/terminal.c

@@ -3965,7 +3965,8 @@ update_system_term(term_T *term)
 	else
 	    pos.col = 0;
 
-	screen_line(curwin, term->tl_toprow + pos.row, 0, pos.col, Columns, 0);
+	screen_line(curwin, term->tl_toprow + pos.row, 0, pos.col, Columns, -1,
+									    0);
     }
 
     term->tl_dirty_row_start = MAX_ROW;
@@ -4088,7 +4089,7 @@ term_update_window(win_T *wp)
 #ifdef FEAT_MENU
 				+ winbar_height(wp)
 #endif
-				, wp->w_wincol, pos.col, wp->w_width,
+				, wp->w_wincol, pos.col, wp->w_width, -1,
 #ifdef FEAT_PROP_POPUP
 				popup_is_popup(wp) ? SLF_POPUP :
 #endif

src/testdir/test_conceal.vim

@@ -389,28 +389,35 @@ func Test_conceal_eol()
 endfunc
 
 func Test_conceal_mouse_click()
-  enew!
+  call NewWindow(10, 40)
   set mouse=a
   setlocal conceallevel=2 concealcursor=nc
   syn match Concealed "this" conceal
   hi link Concealed Search
-  call setline(1, 'conceal this click here')
-  redraw
-  call assert_equal(['conceal  click here '], ScreenLines(1, 20))
 
-  " click on the space between "this" and "click" puts cursor there
+  " Test with both 'nocursorline' and 'cursorline', as they use two different
+  " code paths to set virtual columns for the cells to clear.
+  for cul in [v:false, v:true]
+    let &l:cursorline = cul
+
+    call setline(1, 'conceal this click here')
+    call assert_equal([
+          \ 'conceal  click here                     ',
+          \ ], ScreenLines(1, 40))
+
+    " Click on the space between "this" and "click" puts cursor there.
     call test_setmouse(1, 9)
     call feedkeys("\<LeftMouse>", "tx")
     call assert_equal([0, 1, 13, 0, 13], getcurpos())
-  " click on 'h' of "here" puts cursor there
+    " Click on 'h' of "here" puts cursor there.
     call test_setmouse(1, 16)
     call feedkeys("\<LeftMouse>", "tx")
     call assert_equal([0, 1, 20, 0, 20], getcurpos())
-  " click on 'e' of "here" puts cursor there
+    " Click on 'e' of "here" puts cursor there.
     call test_setmouse(1, 19)
     call feedkeys("\<LeftMouse>", "tx")
     call assert_equal([0, 1, 23, 0, 23], getcurpos())
-  " click after end of line puts cursor on 'e' without 'virtualedit'
+    " Click after end of line puts cursor on 'e' without 'virtualedit'.
     call test_setmouse(1, 20)
     call feedkeys("\<LeftMouse>", "tx")
     call assert_equal([0, 1, 23, 0, 24], getcurpos())
@@ -429,19 +436,19 @@ func Test_conceal_mouse_click()
 
     set virtualedit=all
     redraw
-  " click on the space between "this" and "click" puts cursor there
+    " Click on the space between "this" and "click" puts cursor there.
     call test_setmouse(1, 9)
     call feedkeys("\<LeftMouse>", "tx")
     call assert_equal([0, 1, 13, 0, 13], getcurpos())
-  " click on 'h' of "here" puts cursor there
+    " Click on 'h' of "here" puts cursor there.
     call test_setmouse(1, 16)
     call feedkeys("\<LeftMouse>", "tx")
     call assert_equal([0, 1, 20, 0, 20], getcurpos())
-  " click on 'e' of "here" puts cursor there
+    " Click on 'e' of "here" puts cursor there.
     call test_setmouse(1, 19)
     call feedkeys("\<LeftMouse>", "tx")
     call assert_equal([0, 1, 23, 0, 23], getcurpos())
-  " click after end of line puts cursor there with 'virtualedit'
+    " Click after end of line puts cursor there with 'virtualedit'.
     call test_setmouse(1, 20)
     call feedkeys("\<LeftMouse>", "tx")
     call assert_equal([0, 1, 24, 0, 24], getcurpos())
@@ -457,9 +464,48 @@ func Test_conceal_mouse_click()
     call test_setmouse(1, 32)
     call feedkeys("\<LeftMouse>", "tx")
     call assert_equal([0, 1, 24, 12, 36], getcurpos())
+    set virtualedit&
 
-  bwipe!
+    " Test with a wrapped line.
-  set mouse& virtualedit&
+    call setline(1, ['conceal this click here']->repeat(3)->join())
+    call assert_equal([
+          \ 'conceal  click here conceal  cli        ',
+          \ 'ck here conceal  click here             ',
+          \ ], ScreenLines([1, 2], 40))
+    " Click on boguscols puts cursor on the last char of a screen line.
+    for col in range(33, 40)
+      call test_setmouse(1, col)
+      call feedkeys("\<LeftMouse>", "tx")
+      call assert_equal([0, 1, 40, 0, 40], getcurpos())
+    endfor
+
+    " Also test with the last char of a screen line concealed.
+    setlocal number signcolumn=yes
+    call assert_equal([
+          \ '    1 conceal  click here conceal       ',
+          \ '       click here conceal  click h      ',
+          \ '      ere                               ',
+          \ ], ScreenLines([1, 3], 40))
+    call test_setmouse(1, 34)
+    call feedkeys("\<LeftMouse>", "tx")
+    call assert_equal([0, 1, 32, 0, 32], getcurpos())
+    call test_setmouse(2, 7)
+    call feedkeys("\<LeftMouse>", "tx")
+    call assert_equal([0, 1, 37, 0, 37], getcurpos())
+    " Click on boguscols puts cursor on the last char of a screen line.
+    for col in range(35, 40)
+      call test_setmouse(1, col)
+      call feedkeys("\<LeftMouse>", "tx")
+      call assert_equal([0, 1, 34, 0, 34], getcurpos())
+      call test_setmouse(2, col)
+      call feedkeys("\<LeftMouse>", "tx")
+      call assert_equal([0, 1, 68, 0, 68], getcurpos())
+    endfor
+    setlocal number& signcolumn&
+  endfor
+
+  call CloseWindow()
+  set mouse&
 endfunc
 
 " Test that cursor is drawn at the correct column when it is after end of the

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    184,
 /**/
     183,
 /**/

src/vim.h

@@ -627,6 +627,7 @@ extern int (*dyn_libintl_wputenv)(const wchar_t *envstring);
 // flags for screen_line()
 #define SLF_RIGHTLEFT	1
 #define SLF_POPUP	2
+#define SLF_INC_VCOL	4
 
 #define MB_FILLER_CHAR '<'  // character used when a double-width character
 			    // doesn't fit.